Series boiler



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sERIE BOILER Filed Nov. 10, 1931 5 Sheets-Sheet l fram fcedpump INVENTOR ATTORNEY Oct. 2, 1934. J. FLETCHER 1,975,096

SERIES BOILER Filed Nov. 10, 1951 3 Sheets-Sheet 2 l &Lg.2 23 l 5 5 INVENTOR flames F 7 2% ATTORNEY QCiQ 2, 1934-. J FLETCHER 1,975,96

SERIES BOILER Filed Nov. 10, 1931 5 Sheets-Sheet 5 INVENTOR ATTORNEY (ill Patented Oct. 2, 1934 PATENT OFFICE SERIES BOILER.

James Fletcher, West New Brighton, Staten Island, N. Y., assignor to The Babcock & Wil- New Jersey cox Company, Bayonne, N. J., a corporation of Application November 10, 1931, Serial No. 574,075

4 Claims. (Cl. 122-250) This invention relates to a vapor generator, and more particularly stated the invention presents an improvement over the invention disclosed in co-pending application Serial Number 450,348 filed in the United States Patent Office May '7, 1930, by Howard J. Kerr, and entitled Steam boiler, and further relates to the means of equalizing conditions in a multiplicity of conduits in the type of vapor generator set forth in the co-pending application of JamesFletcher et a1. Serial No. 574,076 filed Nov. 10, 1931 and relating to a vapor generator and method of operating the same.

Specifically stated, the present invention comprises a vapor generator having a multiplicity of long small bore conduits having liquid entering at one end and delivering moisture free vapor at the other end and including no drum;

In vapor generators of this character the liquid volume within the generator is always at a minimum, and as referred to in the co-pending application of James Fletcheret a1. above identified means are provided with vapor generators of this character, and particularly with the one of the present invention, when operating the same, for maintaining a preponderance of liquid throughout the major length of each of the small bore conduits.

In the operation of such a generator, regardless of the fact that the long small bore conduits may be mechanically equal in resistance to flow, heat absorption and the like, certain inequalities arise in the operation of the" generator with the result that it is desirable to correct these, and accordingly, the present invention particularly relates to means interposed at several locations throughout the length of the vapor generator conduits for equalizing conditions by bringing the fluid of the conduits together and again dividing the same after such equalization, it being preferable to locate these equalizers at points along the concluits where the physical state of the fluid of the respective conduits is the same so that complete mixing will take place, care being taken to avoid locating these equalizers at points where it would be necessary to mix liquid and vapor or mix superheated vapor with saturated vapor.

The present invention therefore, comprises a vapor generator having a multiplicity of long small bore conduits receiving liquid at one end and delivering superheated vapor at the other end and intermediately of which and at points where there is no physical change in the state of the fluid in the conduits, the fluids are mixed,

thus equalizing flow and temperature conditions.

With the above and other objects in view, 1 will now describe, in connection with the accompanying drawings'forming a part of this specification, a specific embodiment which the invention may take in practice, and which is herewith described not in a limiting sense, but with the purpose of complying with the patent statutes.

In the accompanying drawings,

Figure 1 is a vertical central section through a vapor generator of the character hereinbefore referred to. 1

Figure 2is a side elevation thereof with the outside casing removed.

Figure 3 is asectional view on the line 33 of Fi 2.

Figure 4 is a sectional view on the line of Fig. 2.

Figure 5 is a sectional view on the line 5-5 of Fig. 2.

Figure 6 is a vertical longitudinal section of an equalizer constructed in accordance with'the present invention, and

Figure 7 is a top plan view of the same.

The vapor generator comprises a furnace 1 having walls 2 suitably insulated as shown at 3 and including a casing 4 to maintain the insulation in place. Through the walls 2 there is an opening 5 closed by refractory material 6 and a door '7 mounted in a frame 8. The bottom portion 9; and its closure 10, are carried in a suitable structural or welded steel frame work 11, a central opening 12 receives any usual type of fuel burner 13 for either solid or liquid fuel, but the burner in this instance is illustrated as a mechanical type atomizer for liquid fuel and discharges through burner tile 14, said burner being surrounded by an air box 15 and the burner proper being bed with fuel through the fuel line 16.

The furnace portion of the generator is surmounted by a sscondary combustion chamberl'l. having a contracted portion 18 ending in a flue 19 leading to a stack 20, which stack may be controlled by a damper, the whole being supported by means of structural steel framework of any suitable form. A jacket 22 covers the secondary combustion chamber 1'7 and its contracted portion outside the refractory wall 2 and its attendant insulation.

Liquid to be convertedinto vapor under pressure is fed to a header 23 from which originate two parallel long small bore conduits 24 and 25, each being the series type and being formed sinuously in layers by suitable bending as shown in connection with Figs. 1 to" 5 inclusive. The

portions located in the flue 19 have much greater length than the remaining portions and extend down to the juncture of the flue 19 with the -and then emerge inte an equalizing or mixing means 27 which brings the discharge from the two conduits into mixing relation in a manner to be hereinafter described, whereby the fluid from the respective conduits comingles "and equalizes as toquantity and temperature, again separating into the two conduits 24 and 25 which are then coiled upwardly through the constricted portion 18 of the secondary combustion chamber 17 until they again emerge and enter an equalizing means 28, in which the vapor from the two conduits is comingled for equalization of temperature and distribution, the conduits then being again divided and coiled within the secondary combustion chamber 17 to the top' of the restricted portion 18 thereof and emerging, as'indicated at 29, to anoutiet equalizing header 30 where discharge from the two conduits is again comingled for'fluid and temperature equal-' ization. h

It will be observed that by these equalizing means the group oi conduits is definitely segregated into four sections, namely, an econcmizer section A with its initial entrance at 23, a water wall section B with its initial entrance at 21, a steam generating section C with its initial entrance from equalizing means 2'7, and a superheating section D with its initial entrance from the equalizing means 28, the flnal outlet of superheated vapor being from 30.

From the foregoing, it will be clear that the equalizing means 26, 2'1, 28, and 30 are each located at a position where there is no difierence in physical state of the fluid passing thereto, so that better mixing is insured than could be accomplished were attempts made to mix fluids/0t difierent physical characteristics, as, for instance, steam and water, or saturated and superheated steam.

It likewise be apparent that the grouping of the respective portions of the conduits is such that each represents a continuous sinuous fluid flow path of great length and small diameter from liquid entrance to superheated vapor outlet, with some portion thereof having fluid flow countercurrent to the hot gases passing thereover while other portions thereof have fluid flow concurrent with the gases passing thereover.

The grouping of the conduit areas exposed to heat and their arrangement with respect to the furnace, secondary combustion chamber 17 and flue 19, is such that insofar as arrangement is considered, the heat absorbed by any one conduit is substantially equal to the heat absorbed by any other conduit, with the result that heat input to each conduit for a given combustion condition is approximately constant and that the furnace and flue are so constructed that the. re-

I sidual heat therein is at a Also, the arrangement of conduits 24 and 25 is such, as shown in Figs; 2 to 5 inclusive, that the length of one conduit approximately equals that of the other, the resistance to flow'ln the conduits being therefore substantially equivalent mechanically.

In the form of the invention shown the conduits 24 and 25 are coiled from the furnace chamber 1, upon the wall of which they are supported up through the contracted portion 18 of the secondary combustion chamber, 17, where they are then arranged in sinuous form crossing and recrossing at right angles and some of the being extended to engage the wall for support as indicated at 40.v

The entrance header 23 is connected to a liquid supply pipe 32 which, in turn, is connected to a pump not shown in the drawings,.but is clearly illustrated in a copending application of James Fletcher Nov. 10, 19 31, Ser. No."574,076, which may be so controlled as to insure/a. preponderance of the length of each conduit being full of water.

The vapor generator just described comprises but two conduits 24 and 25, but any number of conduits in excess of two may be used, and to that end I have illustrated in Figs. 6 and '7 the type of equalizing means which is embodied in the vapor generator just previously described, except that in the present instance it is applied to only two conduits whereas, in Figs. 6 and 7 it is illustrated as applied to seven conduits.

I This equalizing means comprises a. chamber 32 of substantially cylindrical form, into one side of which enter conduits 33 which are disposed in circumferential arrangement radially and at equal distances from the center line of the cham ber 32.

Out of the chamber 32 at a point concentric therewith leads a combining tube 34 threaded into place in the chamber wall as shown at 35, and which is threaded into place as shown at 36 in one wall of an identical chamber 37 from the opposite wall of which as shown at 38 lead the tubes 39 conforming in arrangement to the tubes 33 and thus there is provided an entrance through the tubes 33 which creates a combining and equalizing action in the chamber 32 from which the water emerges through the combining tube 34 into the second chamber 37 where it is redistributed through the conduits 39, so that in passage through this equalizing means, where the physical characteristics of the fluid are approinmately the same there is produced an equaliza: tion of fluid temperature and a redistribution in the outgoing tubes 39 whereby at various points, as above mentioned during the course of the'fluid, through the boiler equalization of the quality and". quantity of fluid delivered to each tube takes place.

As the fluid enters the equalizing means through the tubes 33 which are spaced radially around the outlet to the combining tube 34, the fluid impinges the opposite wall of chamber 32 and, after thus being intermingled, passes 13! through combining tube 34,- and impinges against the opposite wall of chamber 37 before it emerges through tubes 39, which, like tubes 33, are spaced radially with respect to, and, concentrically surround the end of combining tube 34, the whole equalizing means producing not only a thorough mixing but a regulating pmssure drop.

Where the fluid is led-into the conduits 24 and 25 originally as by the entrance header 23 a single equalizing chamber is utilized and similarly at 148 the exit the two conduits 24 and 25 deliver their steam to an equalizing header of this type from which the steam emerges and is carried by suitable piping to the point of use. 4

While in the foregoing as above stated, I have 15o described a specific embodiment of the present invention, it is nevertheless to be understood that in carrying said invention into practice, I may resort to any and all devices falling within the scope of the appended claims defining my invention.

I claim: 4

1. A once through vapor generator including a plurality of long, smallbore conduits, forming a once through fluid path, means for maintaining liquid throughout a preponderance of the length of said path, said conduits receiving liquid at one end and delivering dry steam at the other, means at the entrance to said path distributing a regulatedflow to each conduit portion, flow combining means intermediate the ends of said path, and in at least one location where the fluid in the path is in the same physical state, to equalize the condition of the fluid from the several conduit portions prior to entrance into the succeeding conduit portions of the flow path, said means comprising a chamber having radially arranged parallel flow entrances discharging against a receiving and mixing surface, a second chamber similar to the aforesaid and for the reversed function of redistribution, the two chambers being connected by a tube.

2. A once through vapor generator including a plurality of long, small bore conduits forming a once through fluid path receiving pressure liquid at one end and delivering vapor at the fluid outlet; and a combined regulating pressure drop, flow equalizing and mixing means in the fluid path between the inlet and outlet, said means comprising a chamber having a plurality of radially arranged parallel flow inlet openings at one end spaced radially with respect to the axis of the chamber and discharging against a receiving and mixing surface formed by the opposite interior end wall of said chamber, an outlet opening formed through the said opposite end wall and centrally positioned with respect to the radially arranged flow inlet openings, and a flow combining tube communicating with said opening and extending. to successive conduits.

3. A once through vapor generator including a plurality of long, small bore conduits forming a once through fluid path receiving pressure liquid at one end and delivering vapor at the fluid outlet; and a combined regulating pressure drop, flow equalizing and mixing means in the fluid path between the inlet and outlet, said means comprising a chamber having a plurality of radially arranged parallel flow inlet openings at one end spaced radially with respect to the axis of the chamber and discharging against a receiving and mixing surface formed by the opposite interior end wall of said chamber, an outlet opening formed through said opposite end wall and centrally positioned with respect to the radially arranged flow inlet openings, a flow combining tube communicating with said outlet opening, and a second chamber similar to the aforesaid having a centrally positioned flow inlet opening at one end communicating with the flow combining tube and discharging against a receiving and mixing surface formed by the opposite end wall of the chamber, and a plurality of parallel flow outlet openings formed through said opposite end wall and spaced radially with respect to the axis of the chamber and communicating with successive conduits.

4. A once through vapor generator including a plurality of long, small bore conduits forming a once through fluid path receiving pressure liquid at one end and delivering vapor at the fluid outlet, and a combined regulating pressure drop, flow equalizing and mixing means in the fluid path between the inlet and outlet of said conduits, said means comprising chambers, and a combining tube joining the chambers, said conduits communicating with said chambers at points geometrically arranged with respect to the said combining tube.

JAMES FLETCHER. 

